Lost book I was reading?

[ramboblk]

Hello, hope someone can help. I was given a Galaxy Tab3 7.0 by my son and he had a bunch of my favourite authors loaded with Kobo.
I read one with no problem, and was half way through the second when it wouldn't come back up to read and I couldn't find it in the list of books? I didn't delete anything and the battery wasn't below 35% charge. He had shown me where to find a return to bookmark, but I can't find anything like that now. He is 400 miles away and can't help. Any ideas would be greatly appreciated. I am not used to using these devices. And to make things worse, I am not sure what the title was, as I chose it at random from 15 titles by the same author.
Thanks in advance for any insight that will help.
Larry in B.C.